Upgrading 18.04 to 20.04

I have Passbolt CE running on 18.04 and have for a while. I want to move to 20.04 and then later from the manual install to the ubuntu package. I snapshotted and backed up my VM and ran through a do-relase-upgrade and after reboot my passbolt is inaccessible. I get 502 nginx error. I’ve since reverted back to my snapshot, but was hoping someone here would shed some light on what happened or what I should do differently on my next go around.

To be clear this was a fully up to date 2.x passbolt and a fully up to date 18.04 install.